Jeremy Saulnier’s fate was sealed when, as a boy, his cousins sat him down in front of such gruesome horror films as “Dawn of the Dead,” during which he beheld all manner of zombie dismemberment and ingestion of human flesh.

“My cousins from Reston [Virginia] kind of introduced me to some really graphic horror movies early on,” Mr. Saulnier, a native of Alexandria, Virginia, told The Washington Times. “They were goofing around, making me watch heads explode. That also played into my trying to reverse engineer what was happening” as far as the special effects went.

Little wonder then that Mr. Saulnier began making films with a camera borrowed from the District’s Gallaudet University, where his mother worked, trying to imitate the splatter cinema he was far too young to see but nonetheless had courtesy of his relatives.

Soon it was off to New York University film school. Small projects and full-length features followed. Now Mr. Saulnier’s first studio-released picture, “Green Room,” will open in the District Friday.

The film follows a group of death metal bandmates who venture to a remote headbanger’s club in remote Oregon for a gig. An act of violence occurs in the titular musicians’ break room, which leads to the band being locked there, fighting for lives.

In keeping with Mr. Saulnier’s childhood inspirations, the violent, graphically gory film is certainly not for the squeamish.

“It’s not supposed to go down easy, it’s supposed to be at times brutal and hard to digest,” Mr. Saulnier said of the intense horror/suspense thriller. “I think people are appreciating the fact that despite the graphic nature of the violence, it doesn’t play as gratuitous.”

While certainly well within the horror exploitation wheelhouse, Mr. Saulnier believes his film is more akin to such 1980s action entries as “Commando.” Given its premise of outgunned heroes trapped in an enclosed location while hordes of enemies attempt to get them, it also bears the fingerprint of “Assault on Precinct 13” by John Carpenter, one of Mr. Saulnier’s favorite filmmakers.

“There’s certainly more cinematic, traditional action sequences, because this is entertainment after all,” Mr. Saulnier said.

“Green Room” features recognizable young actors like Imogen Poots and Anton Yelchin, but its most high-wattage actor is none other than Patrick Stewart as the metal club’s devious owner, Darcy Banker. While the British thespian has certainly played his share of heavies in his storied career, the 75-year-old, classically trained actor is most known to the popular culture thanks to “Star Trek: The Next Generation” and the “X-Men” films.

“We were about 10 days from production and we were in a pickle,” Mr. Saulnier says of going ahead without his chief villain yet cast. Fortunately, he and Mr. Stewart had recently signed to the same management company, so a corporate worker passed along the “Green Room” script to Mr. Stewart, who was looking to try something different and immediately came onboard.

Casting the actor known to millions as the heroic Captain Jean-Luc Picard reassured Mr. Saulnier’s investors that they did indeed have a viable product on their hands.

“He’s very generous and very dedicated, so he puts you at ease,” Mr. Saulnier said of Mr. Stewart. “After a few days he realized that I did have the whole film pre-visualized and edited in my head. And he sort of let down his guard and trusted me,” Mr. Saulnier said of his villain.

“I was nervous when we first showed him a cut of the movie, because he took a big risk,” Mr. Saulnier said of Mr. Stewart agreeing to work with a relatively unseasoned director on a horror flick, but “he is really supporting the movie and is delighted to see it.”

While the discussion with The Times took place in Mr. Saulnier’s District haunts, he now lives in Brooklyn with his wife, not far from his old NYU stomping grounds.

When asked what he would say to moviegoers who might accuse him of making “Green Room” perhaps too gratuitously gruesome, the writer-director offers a simple solution: Go see it.

“I’m shocked by those who comes to me afterwards and says, ‘I really don’t like horror films or I don’t like violent films, but I really loved yours,’” he said. “Because if you can endure the experience, it’s supposed to be thrilling so that you feel the peril. And of course it will end, and you will feel the elation of survival.”